To develop the Javanese ginger Bangle (Zingiber purpureum), which contains neurotrophic phenylbutenoid compounds named banglenes 1 and 2, as a functional food additive for protection of neurodegenerative disease, we investigated conversion method from 3 to 1 and 2 under practical conditions available in food processing steps. After several trials, we found that dimerization of 3 proceeded smoothly under refluxing EtOH/H2O (1/3) in the presence of ubiquinone (0.1 eq) in sealed tube, giving rise to 1 and 2 in 54% yield. When this condition was applied for 70% EtOH extract of bangle, content of 1 and 2 in the extract was increased 2-fold by 2.1%.
NakaiM., IizukaM., MatsuiN., HosogiK., ImaiA., AbeN., ShiraishiH., HirataA., YagiY., JobuK., YokotaJ., KatoE., HosodaS., YoshiokaS., HaradaK., KuboM., FukuyamaY., MiyamuraM. (2016) Bangle (Zingiber purpureum) improves spatial learning, reduces deficits in memory, and promotes neurogenesis in the dentate gyrus of senescence-accelerated mouse P8. Journal of Medicinal Food, 19, 435–441.
5.
Unpublished data.
6.
AronovitchC., MazurY. (1985) Oxidative cleavage of olefins adsorbed on inorganic supports with reactions in dry media. Journal of Organic Chemistry, 50, 149–150.
7.
EriksenJ., FooteC.S., ParkerT.L. (1977) Photosensitized oxygenation of alkenes and sulfides via a non-singlet-oxygen mechanism. Journal of American Chemical Society, 99, 6455–6456.
